A transmission for working machines having a working transmission mechanism and a drive transmission mechanism is disclosed, for example, in Japanese Utility Model Laid-Open Publication No. HEI-1-32113. This transmission will be described with reference to FIGS. 18 and 19 hereof.
Referring to FIGS. 18 and 19, a shaft 202 is rotatably mounted to a transmission case 201. An outside pipe 203 to be a support is attached to the shaft 202. An inside pipe 204 is rotatably fitted in the outside pipe 203. A change lever 205 is connected to the inside pipe 204. An arm 209 is mounted on the inside pipe 204. The arm 209 has an elongated hole 210. A pin 211 passes through the elongated hole 210. An end of the pin 211 is fitted in a change shaft 212. The change shaft 212 is connected to a drive transmission mechanism.
An arm 215 is mounted on a distal end portion of the shaft 202. A distal end portion of a pin 217 mounted to a change shaft 219 via a boss 218 is fitted into an elongated hole 216 formed in the arm 215. The change shaft 219 is connected to a working transmission mechanism.
As shown in FIG. 18, a swing of the change lever 205 in the vertical direction in the figure causes a vertical swing of the arm 215. With this, as shown in FIG. 19, the change shaft 219 rotates via the pin 217 and the boss 218 for a gear change of the working transmission mechanism.
As shown in FIG. 19, a swing of the change lever 205 in the vertical direction in the figure causes the arm 209 to swing, with which the change shaft 212 axially moves via the pin 211 for a gear change of the drive transmission mechanism.
A gear change of the drive transmission mechanism is made by a horizontal operation of the change lever 205. A gear change of the working transmission mechanism is made by a vertical operation of the change lever 205. The vertical and horizontal shift controls are complicated and awkward for a transmission with a drive transmission mechanism and a working transmission mechanism both for multi-speed change. There are a large number of components between the change lever 205 and the drive transmission mechanism and working transmission mechanism, resulting in a large number of assembly steps and increased costs.
It is thus desired to improve a transmission for working machines to facilitate shift control and reduce costs of the transmission.